The invention relates to a method for automatically punching the tuyeres of a converter.
Converters are extensively employed for smelting metals. In smelting copper with a converter, air is blown into a matte containing 40% to 60% copper, and the remaining contents, iron and sulfur, are removed by converting them into iron oxides and sulfur dioxide so as to obtain blister copper containing about 98% copper. The air blowing nozzles are relatively small in diameter, typically several tens of millimeters. Molten materials in the converter is solidified and form encrustations at inner tips of the tuyeres by adiabatically cooling the molten materials with blowing air. In this case, it becomes difficult to supply sufficient amount of air into the converters, as a result of which the converting operation must be suspended, when the solidified encrustations has been grown up. Therefore, mechanical punching operation is carried out in order to remove the solidified encrustations frequently.
Heretofore, an operator seated on an operator's seat on the carriage of a mechanical puncher having punching rods coupled to a fluid-driven cylinder visually confirmed the positions of the tuyeres of a converter and controlled the running and stopping of the carriage to achieve a punching operation to clear the nozzles. Accordingly, the punching operation could not be accomplished without considerable operator skill. Furthermore, with a mechanical puncher having four punching rods driven by a single cylinder in order to reduce the time required for punching operation, much higher skill is required for the operator to accurately position the carriage correctly with respect to the intended tuyeres. The working environmental conditions around the converter are poor because of the presence of noise, heat, dust, etc. In addition, there is the danger that the converter may "foam", that is jet out high-temperature molten materials. The provision of a method for automatically and positively punching the tuyeres and an apparatus for practicing the method has been strongly demanded in the art.
Accordingly, an object of this invention is to provide a method for automatically, positively and safely punching the tuyeres of a converter.